Despite the plush surroundings - free moisturiser and towels the size of duvet covers - Chelsea's KX gym is home to one of the toughest workout classes in London. Combining functional movements and the sort of exercises you'd normally see on the World's Strongest Man, X-Fit is a brutal test of core strength, grip and cardio. Check out the video - and then read our December issue to see how you can mimic these moves in your own gym.

For more on KX X-Fit see kxgym.co.uk